Mobile terminal and controlling method thereof

ABSTRACT

A mobile terminal includes a controller and a display unit for displaying a stereoscopic image including a first image provided to a left eye of a user and a second image provided to a right eye of the user. The controller detects at least one same object between the first and second images, and determines a distance between a point at which the detected at least one same object is positioned in the first image and a point at which the detected at least one same object is positioned in the second image. When the determined distance is equal to or greater than a preset critical value, the controller changes a position of the at least one same object in each of the first and second images to decrease the distance to less than the preset critical value.

CROSS-REFERENCE TO RELATED APPLICATIONS

Pursuant to 35 U.S.C. §119(a), this application claims the benefit ofearlier filing date and right of priority to Korean Application No.10-2010-0067815, filed on Jul. 14, 2010, the contents of which arehereby incorporated by reference herein in its entirety.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a mobile terminal, and moreparticularly, to a mobile terminal and controlling method thereof.Although the present invention is suitable for a wide scope ofapplications, it is particularly suitable for securing visual comfort ofa user when viewing a stereoscopic image.

2. Discussion of the Related Art

Generally, terminals may be classified as mobile/portable terminals orstationary terminals. The mobile terminals may be further classified ashandheld terminals or vehicle mounted terminals according to theirportability.

As terminal functions are diversified, the terminal may be implementedas a multimedia player performing various functions such as photographyor videography, playback of music or video, game play, broadcastreception and the like, for example.

Ongoing efforts exist to support and increase the functionality of theterminal. Such efforts include software and hardware improvements, aswell as changes and improvements to the structural components which formthe terminal.

Recently, terminals have developed such that a three-dimensional (3D)image can be displayed on a display unit of a terminal. However, when a3D stereoscopic image is displayed, a terminal user may experiencevisual discomfort, such as dizziness and the like, caused by thedisplayed image. Therefore, what is needed is a 3D imagecorrecting/displaying method for relieving the visual discomfortexperienced by the user.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a mobile terminal andcontrolling method thereof that substantially obviate one or moreproblems due to limitations and disadvantages of the related art.

An object of the present invention is to provide a mobile terminal andcontrolling method thereof, by which a user can be provided with a moreconvenient stereoscopic image appreciating environment.

Another object of the present invention is to provide a mobile terminaland controlling method thereof, by which a 3D depth of a specific objectin a stereoscopic image can be adjusted not to cause visualinconvenience to a user.

It is to be understood that technical problems to be solved by thepresent invention are not limited to the aforementioned technicalproblems and other technical problems which are not mentioned will beapparent from the following description to the person with an ordinaryskill in the art to which the present invention pertains.

To achieve these objects and other advantages and in accordance with thepurpose of the invention, as embodied and broadly described herein, amobile terminal comprises a controller and a display unit controlled bythe controller and configured to display a stereoscopic image, thestereoscopic image comprising a first image provided to a left eye of auser and a second image provided to a right eye of the user. Thecontroller detects at least one same object between the first and secondimages and determines a distance between a point at which the detectedat least one same object is positioned in the first image and a point atwhich the detected at least one same object is positioned in the secondimage. When the determined distance is equal to or greater than a presetcritical value, the controller changes a position of the at least onesame object in each of the first and second images to decrease thedistance between the point at which the at least one same object ispositioned in the first image and the point at which the at least onesame object is positioned in the second image to less than the presetcritical value, and the controller displays the changed first and secondimages on the display unit.

In one aspect of the invention, the display unit comprises an imagedisplaying means and a parallax generating means provided over the imagedisplaying means to change at least one of a propagation direction and avibration direction of a light generated from the image displayingmeans. In another aspect, the controller detects the at least one sameobject between the first and second images by a block search algorithmor an object tracking algorithm. In a further aspect, the controllerchanges the position of the at least one same object in each of thefirst image and second image by moving the at least one same objectcloser to a center point between the point at which the at least onesame object is positioned in the first image and the point at which theat least one same object is positioned in the second image by the samedistance.

In one aspect of the invention, the controller displays the at least onesame object with a prescribed visual effect before changing the positionof the at least one same object. The mobile terminal may furthercomprise a user input unit configured to receive a user command, whereinif the at least one same object with the prescribed visual effect isselected by the user command, the controller only changes a position ofthe selected object in each of the first image and second image. In afurther aspect, each time the selection is made, the controller changesthe position of the selected object by a predetermined distance.

The mobile terminal may further comprise a user input unit configured toreceive a user command, wherein if the at least one same object with theprescribed visual effect is selected by the user command, the controllerdisplays a menu window in the vicinity of the selected object to enablethe user to select a manual execution of the position change or anautomatic execution of the position change of the selected object. Inone aspect, if the manual execution is selected from the menu window,the controller displays a scroll bar for adjusting a distance of theposition change of the selected object. In another aspect, if theautomatic execution is selected from the menu window, the controllerchanges the position of the selected object in each of the first imageand second image such that the distance between the point at which theselected object is positioned in the first image and the point at whichthe selected object is positioned in the second image is less than thepreset critical value.

The controller may display a convergence object positioned at a sameposition in the first and second images with a different prescribedvisual effect according to a relative level of a stereoscopic effect ofthe at least same object.

In one aspect of the invention, the first image and the second imagecorrespond to one video frame, wherein when the position of the at leastone same object is changed in each of the first image and second image,if a lost space is generated in the one video frame, the controllercontrols an image corresponding to the lost space to be inserted in avideo frame next to or previous to the one video frame.

In a further aspect of the invention, when the position of the at leastone same object is changed in one of the first image and second image,if a lost space is generated, the controller controls an imagecorresponding to the lost space in the other of the first image andsecond image to be inserted in the lost space in the one of the firstimage and second image.

In another aspect of the invention, the preset critical value is adistance corresponding to a binocular interval of the user.

The present invention may also be embodied as a method of controlling amobile terminal, the method comprising detecting at least one sameobject between a first image and a second image displayed on a displayunit, wherein the first image and second image together form astereoscopic image, calculating a distance between a point at which thedetected at least one same object is positioned in the first image and apoint at which the detected at least one same object is positioned inthe second image, and determining whether the calculated distance isequal to greater than a preset critical value. When the calculateddistance is equal to or greater than the preset critical value, changinga position of the at least one same object in each of the first andsecond images to decrease the distance between the point at which thedetected at least one same object is positioned in the first image andthe point at which the detected at least one same object is positionedin the second image to less than the preset critical value, anddisplaying the changed first and second images on the display unit.

It is to be understood that the advantages that can be obtained by thepresent invention are not limited to the aforementioned advantages andother advantages which are not mentioned will be apparent from thefollowing description to the person with an ordinary skill in the art towhich the present invention pertains.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this application, illustrate embodiment(s) of the invention andtogether with the description serve to explain the principle of theinvention.

FIG. 1 is a block diagram of a mobile terminal according to oneembodiment of the present invention.

FIG. 2 is a front perspective view of a mobile terminal according to oneembodiment of the present invention.

FIG. 3 is a front view of a mobile terminal according to one embodimentof the present invention.

FIG. 4 is a diagram illustrating the principle of binocular disparity.

FIG. 5 is a diagram illustrating a sense of distance and 3D depthattributed to binocular disparity.

FIG. 6 illustrates a method for displaying a 3D stereoscopic image on aparallax barrier type display unit according to embodiments of thepresent invention.

FIG. 7 is a diagram for describing stereoscopy of a planar object.

FIG. 8 illustrates a display configuration resulting from combiningright and left eye images together to indicate a difference betweenarranged positions in the images.

FIG. 9 illustrates a block search algorithm according to one embodimentof the present invention.

FIG. 10 illustrates a method of calculating an arranged distancedifference between objects appearing in left and right eye imagesaccording to one embodiment of the present invention.

FIG. 11 illustrates display configurations for searching left and righteye images for the same object in a mobile terminal according to oneembodiment of the present invention.

FIG. 12 illustrates a method of performing position correction accordingto one embodiment of the present invention.

FIG. 13 illustrates a method of performing position correction accordingto one embodiment of the present invention.

FIG. 14 illustrates a method of compensating an image according to oneembodiment of the present invention.

FIG. 15 illustrates a method of measuring and setting a criticaldistance according to embodiments of the present invention.

FIG. 16 illustrates a method of correcting a stereoscopic imageaccording to one embodiment of the present invention.

FIG. 17 illustrates a menu screen for setting a method of correcting astereoscopic image according to embodiments of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

In the following detailed description, reference is made to theaccompanying drawing figures which form a part hereof, and which show byway of illustration specific embodiments of the invention. It is to beunderstood by those of ordinary skill in this technological field thatother embodiments may be utilized, and structural, electrical, as wellas procedural changes may be made without departing from the scope ofthe present invention. Wherever possible, the same reference numberswill be used throughout the drawings to refer to the same or similarparts.

As used herein, the terms ‘module’, ‘unit’ and ‘part’ are used forelements in order to facilitate the disclosure only. Therefore,significant meanings or roles are not given to the terms themselves andit is understood that ‘module’, ‘unit’ and ‘part’ can be used togetheror interchangeably.

The present invention can be applicable to various types of terminals.Examples of such terminals include mobile as well as stationaryterminals, such as mobile phones, user equipments (UEs), smart phones,digital televisions (DTVs), computers, digital broadcast terminals,personal digital assistants (PDAs), portable multimedia players (PMPs)and navigators.

By way of non-limiting example only, further description will be withregard to a mobile terminal 100. However, it should be noted that suchteachings may apply equally to other types of terminals.

FIG. 1 is a block diagram of a mobile terminal 100 in accordance with anembodiment of the present invention. FIG. 1 shows that the mobileterminal 100 according to one embodiment of the present inventionincludes a wireless communication unit 110, an audio/video (A/V) inputunit 120, a user input unit 130, a sensing unit 140, an output unit 150,a memory 160, an interface unit 170, a controller 180, a power supply190, and the like. FIG. 1 shows the mobile terminal 100 having variouscomponents, but it is understood that implementing all of theillustrated components is not a requirement. Greater or fewer componentsmay alternatively be implemented.

The wireless communication unit 110 may include one or more componentsfacilitating wireless communication between the mobile terminal 100 anda wireless communication system or network within which the mobileterminal 100 is located. For example, the wireless communication unit110 can include a broadcast receiving module 111, a mobile communicationmodule 112, a wireless Internet module 113, a short-range communicationmodule 114, a position-location module 115, and the like.

The broadcast receiving module 111 receives a broadcast signal and/orbroadcast associated information from an external broadcast managingserver via a broadcast channel. The broadcast channel may include asatellite channel and a terrestrial channel.

The broadcast managing server may include a server which generates andtransmits a broadcast signal and/or broadcast associated information, ora server which is provided with a previously generated broadcast signaland/or broadcast associated information and then transmits the providedsignal or information to a terminal. The broadcast signal may beimplemented as a TV broadcast signal, a radio broadcast signal, and adata broadcast signal, among others. If desired, the broadcast signalmay further include a broadcast signal combined with a TV or radiobroadcast signal.

The broadcast associated information may include information associatedwith a broadcast channel, a broadcast program, a broadcast serviceprovider, etc. And, the broadcast associated information can be providedvia a mobile communication network. In one embodiment, the broadcastassociated information can be received by the mobile communicationmodule 112.

The broadcast associated information can be implemented in variousforms. For example, the broadcast associated information may include anelectronic program guide (EPG) of a digital multimedia broadcasting(DMB) system or an electronic service guide (ESG) of a digital videobroadcast-handheld (DVB-H) system.

The broadcast receiving module 111 may be configured to receivebroadcast signals transmitted from various types of broadcast systems.By nonlimiting example, such broadcasting systems include a digitalmultimedia broadcasting-terrestrial (DMB-T) system, a digital multimediabroadcasting-satellite (DMB-S) system, a digital videobroadcast-handheld (DVB-H) system, the data broadcasting system known asmedia forward link only (MediaFLO®) and an integrated services digitalbroadcast-terrestrial (ISDB-T) system. The broadcast receiving module111 may also be configured for other broadcasting systems in addition tothe digital broadcasting systems mentioned above. The broadcast signaland/or broadcast associated information received by the broadcastreceiving module 111 may be stored in a suitable device, such as amemory 160.

The mobile communication module 112 transmits/receives wireless signalsto/from one or more network entities (e.g., base station, externalterminal, server, etc.). Such wireless signals may represent audio,video, and data according to text/multimedia messagetransmissions/receptions, among others.

The wireless Internet module 113 supports Internet access for the mobileterminal 100. The wireless Internet module 113 module may be internallyor externally coupled to the mobile terminal 100. In one embodiment, awireless Internet technology can include WLAN (Wireless LAN) (Wi-Fi),Wibro (Wireless broadband), Wimax (World Interoperability for MicrowaveAccess), HSDPA (High Speed Downlink Packet Access), etc.

The short-range communication module 114 facilitates relativelyshort-range communications. Suitable technologies for implementing theshort-range communication module 114 include radio frequencyidentification (RFID), infrared data association (IrDA), ultra-wideband(UWB), as well at the networking technologies commonly referred to asBluetooth® and ZigBee®, to name a few.

The position-location module 115 identifies or obtains the location ofthe mobile terminal 100. If desired, the position-location module 115may be implemented with a global positioning system (GPS) module.

Referring to FIG. 1, the audio/video (A/V) input unit 120 is configuredto provide an audio or video signal input to the mobile terminal 100. Asshown, the A/V input unit 120 includes a camera 121 and a microphone122. The camera 121 receives and processes image frames of stillpictures or video obtained by an image sensor in a video call mode or aphotographing mode. The processed image frames can be displayed on thedisplay 151.

The image frames processed by the camera 121 can be stored in the memory160 or can be externally transmitted via the wireless communication unit110. Optionally, at least two cameras 121 can be provided on the mobileterminal 100 according to implementation.

The microphone 122 receives an external audio signal while the mobileterminal is in a particular mode, such as phone call mode, recordingmode or voice recognition. The audio signal is processed and convertedinto electric audio data. The processed audio data is then transformedinto a format transmittable to a mobile communication base station viathe mobile communication module 112 in case of a call mode. Themicrophone 122 includes assorted noise removing algorithms to removenoise generated in the course of receiving the external audio signal.

The user input unit 130 generates input data responsive to usermanipulation of an associated input device or devices. Examples of suchinput devices include a keypad, a dome switch, a touchpad (e.g., staticpressure/capacitance), a jog wheel, a jog switch, etc.

The sensing unit 140 provides sensing signals for controlling operationsof the mobile terminal 100 using status measurements of various aspectsof the mobile terminal. For example, the sensing unit 140 may detect anopen/closed status of the mobile terminal 100, relative positioning ofcomponents (e.g., a display and keypad) of the mobile terminal 100, achange of position of the mobile terminal 100 or a component of themobile terminal 100, a presence or absence of user contact with themobile terminal 100, orientation of the mobile terminal 100 oracceleration/deceleration of the mobile terminal 100.

In one embodiment, the mobile terminal 100 may be configured as aslide-type mobile terminal. In this configuration, the sensing unit 140may sense whether a sliding portion of the mobile terminal is open orclosed. Other examples include the sensing unit 140 sensing the presenceor absence of power provided by the power supply 190 or the presence orabsence of a coupling or other connection between the interface unit 170and an external device. The sensing unit 140 can include a proximitysensor 141.

The output unit 150 generates outputs relevant to a user's senses ofsight, hearing, touch and the like. The output unit 150 includes thedisplay 151, an audio output module 152, an alarm unit 153, a hapticmodule 154, a projector module 155 and the like.

The display 151 may visually display (output) information associatedwith the mobile terminal 100. For example, if the mobile terminal isoperating in a phone call mode, the display may provide a user interface(UI) or graphical user interface (GUI) which includes informationassociated with placing, conducting, and terminating a phone call. Inanother example, if the mobile terminal 100 is in a video call mode or aphotographing mode, the display 151 may additionally or alternativelydisplay images associated with the video call mode or photographing modeon the UI or GUI.

The display module 151 may be implemented using known displaytechnologies including, for example, a liquid crystal display (LCD), athin film transistor-liquid crystal display (TFT-LCD), an organiclight-emitting diode display (OLED), a flexible display and athree-dimensional display. The mobile terminal 100 may include one ormore of such displays.

Some of the above displays can be implemented as a transparent oroptically transmissive type, hereinafter called a transparent display. Arepresentative example of the transparent display is a transparent OLED(TOLED) or the like. A rear configuration of the display 151 may beimplemented as an optically transmissive type as well. In thisconfiguration, a user is able to see an object behind a terminal bodyvia the area occupied by the display 151 of the terminal body.

At least two displays 151 may be provided on the mobile terminal 100 inaccordance with one embodiment. For example, a plurality of displays maybe arranged on a single face of the mobile terminal 100, either spacedapart from each other or built as a single body. Alternatively, theplurality of displays can be arranged on different faces of the mobileterminal 100.

In one embodiment, if the display 151 and a sensor for detecting a touchaction (hereinafter called a ‘touch sensor’) configures a mutual layerstructure (hereinafter called a ‘touchscreen’), a user may use thedisplay 151 as an input device as well as an output device. The touchsensor may be a touch film, a touch sheet, a touchpad or the like.

The touch sensor can convert a pressure applied to a specific portion ofthe display 151, or a variation of capacitance generated from a specificportion of the display 151, into an electric input signal. Moreover, thetouch sensor may detect a touch pressure as well as a touch position orsize.

If a touch input is made to the touch sensor, a signal corresponding tothe touch input is transferred to a touch controller. The touchcontroller processes the signal and then transfers the processed signalto the controller 180. Therefore, the controller 180 is able to knowwhether a prescribed portion of the display 151 is touched.

Referring to FIG. 1, a proximity sensor 141 may be provided to aninternal area of the mobile terminal 100 enclosed by the touchscreen oraround the touchscreen. The proximity sensor 141 detects a presence ornon-presence of an object approaching a prescribed detecting surface, oran object existing around the proximity sensor, by detecting anelectromagnetic field strength or infrared ray without mechanicalcontact. Hence, the proximity sensor 141 may be more durable and havewider utility than a contact type sensor.

The proximity sensor 141 may be a transmissive photoelectric sensor, adirect reflective photoelectric sensor, a minor reflective photoelectricsensor, a radio frequency oscillation proximity sensor, an electrostaticcapacity proximity sensor, a magnetic proximity sensor, an infraredproximity sensor and the like. If the touchscreen includes theelectrostatic capacity proximity sensor, the touchscreen detects theproximity of a pointer using a variation of electric field according tothe proximity of the pointer. In this case, the touchscreen (touchsensor) may be classified as a proximity sensor.

In the following description, for clarity, the action of a pointerapproaching, without contacting, the touchscreen and recognized aslocated on the touchscreen is referred to as a ‘proximity touch’. And,the action of a pointer actually contacting the touchscreen is referredto as a ‘contact touch’. Furthermore, a position on the touchscreen“proximity-touched” by the pointer refers to a position of the pointerthat vertically opposes the touchscreen when the pointer performs theproximity touch.

The proximity sensor 141 detects a proximity touch and a proximity touchpattern (e.g., a proximity touch distance, a proximity touch duration, aproximity touch position, a proximity touch shift state, etc.).Information corresponding to the detected proximity touch action and thedetected proximity touch pattern can be outputted to the touchscreen.

The audio output module 152 functions in various modes including acall-receiving mode, a call-placing mode, a recording mode, a voicerecognition mode, a broadcast reception mode and the like to outputaudio data received from the wireless communication unit 110 or storedin the memory 160. During operation, the audio output module 152 outputsaudio related to a particular function (e.g., call received, messagereceived, etc.). The audio output module 152 may be implemented usingone or more speakers, buzzers, other audio producing devices, andcombinations thereof.

The alarm unit 153 outputs a signal for announcing the occurrence of aparticular event associated with the mobile terminal 100. Events mayinclude a call received event, a message received event and a touchinput received event, for example. The alarm unit 153 may output asignal for announcing the event occurrence by way of vibration as wellas video or audio signal. The video or audio signal can be outputted viathe display 151 or the audio output unit 152. Hence, the display 151 orthe audio output module 152 may be considered part of the alarm unit153.

The haptic module 154 generates various tactile effects that can besensed by a user. Vibration is an example of one of the tactile effectsgenerated by the haptic module 154. Strength and pattern of thevibration generated by the haptic module 154 may be controllable. Forexample, different vibrations can be outputted by being synthesizedtogether or outputted in sequence.

The haptic module 154 may generate tactile effects in addition tovibration. For example, the haptic module 154 may generate the effectattributed to an arrangement of pins vertically moving against acontacted skin surface, the effect attributed to an injection/suctionpower of air though an injection/suction hole, the effect attributed toa skim over a skin surface, the effect attributed to an electrodecontact, the effect attributed to an electrostatic force, the effectattributed to a representation of a hot/cold sense using an endothermicor exothermic device and the like.

The haptic module 154 enables a user to sense the tactile effect througha muscle sense of a finger, arm or the like, as well as to transfer thetactile effect through direct contact. Optionally, at least two hapticmodules 154 can be provided on the mobile terminal 100 in accordancewith one embodiment of the present invention.

The projector module 155 performs an image projector function using themobile terminal 100. The projector module 155 is able to display animage, which is identical to or partially different from an imagedisplayed on the display 151, on an external screen or wall according toa control signal of the controller 180.

In one embodiment, the projector module 155 may include a light sourcegenerating light (e.g., laser) for projecting an image externally, animage producing means for producing an image to output externally usingthe light generated from the light source, and a lens for enlarging theimage to output externally at a predetermined focal distance. Theprojector module 155 can further include a device for adjusting adirection the image is projected by mechanically moving the lens or theentire module.

The projector module 155 may be a cathode ray tube (CRT) module, aliquid crystal display (LCD) module, a digital light processing (DLP)module or the like according to a device type of a display means. In oneembodiment, the DLP module is operated by enabling light generated froma light source to reflect on a digital micro-mirror device (DMD) chip,which is advantageous for downsizing the projector module 155.

In one embodiment, the projector module 155 may be provided in a lengthdirection of a lateral, front or backside direction of the mobileterminal 100. However, it is understood that the projector module 155may be provided to any portion of the mobile terminal 100 according tonecessity.

The memory unit 160 may store various types of data to support theprocessing, control, and storage requirements of the mobile terminal100. Examples of such data include program instructions for applicationsoperating on the mobile terminal 100, contact data, phonebook data,message data, audio data, still picture data, moving picture data, etc.And, a recent use history or a cumulative use frequency of each data(e.g., use frequency of each phonebook data, each message data or eachmultimedia data) can be stored in the memory unit 160. Moreover, datafor various patterns of vibration and/or sound outputted in case of atouch input to the touchscreen may be stored in the memory unit 160.

The memory unit 160 may be implemented using any type or combination ofsuitable volatile and non-volatile memory or storage devices including ahard disk, random access memory (RAM), static random access memory(SRAM), electrically erasable programmable read-only memory (EEPROM),erasable programmable read-only memory (EPROM), programmable read-onlymemory (PROM), read-only memory (ROM), magnetic memory, flash memory,magnetic or optical disk, multimedia card micro type memory, card-typememory (e.g., SD memory, XD memory, etc.), or other similar memory ordata storage device. Furthermore, the mobile terminal 100 may operate inassociation with a web storage for performing a storage function of thememory 160 on the Internet.

The interface unit 170 couples the mobile terminal 100 with externaldevices. The interface unit 170 receives data from the external devices,or is supplied with power, and transfers the data or power to respectiveelements of the mobile terminal 100, or enables data within the mobileterminal 100 to be transferred to the external devices. The interfaceunit 170 may be configured using a wired/wireless headset port, anexternal charger port, a wired/wireless data port, a memory card port, aport for coupling to a device having an identity module, audioinput/output ports, video input/output ports, an earphone port and/orthe like.

The identity module is a chip for storing various types of informationfor authenticating a use authority of the mobile terminal 100, and mayinclude a User Identity Module (UIM), a Subscriber Identity Module(SIM), a Universal Subscriber Identity Module (USIM) and/or the like. Adevice having the identity module (hereinafter called ‘identity device’)can be manufactured as a smart card. Therefore, the identity device isconnectable to the mobile terminal 100 via a corresponding port.

When the mobile terminal 110 is connected to an external cradle, theinterface unit 170 becomes a passage for supplying the mobile terminal100 with power from the cradle or a passage for delivering variouscommand signals input from the cradle by a user to the mobile terminal100. Each of the various command signals input from the cradle, or thepower, may operate as a signal enabling the mobile terminal 100 torecognize that it is correctly loaded in the cradle.

The controller 180 controls the overall operations of the mobileterminal 100. For example, the controller 180 performs control andprocessing associated with voice calls, data communications, videocalls, etc. The controller 180 may include a multimedia module 181 thatprovides multimedia playback. The multimedia module 181 may beconfigured as part of the controller 180, or implemented as a separatecomponent.

Moreover, the controller 180 is able to perform a pattern recognizingprocess for recognizing a writing input or a picture drawing inputcarried out on the touchscreen as characters or images, respectively.

The power supply 190 provides power required by the various componentsof the mobile terminal 100. The power may be internal power, externalpower, or combinations thereof.

Various embodiments described herein may be implemented in acomputer-readable medium using, for example, computer software,hardware, or some combination thereof. For a hardware implementation,the embodiments described herein may be implemented within one or moreapplication specific integrated circuits (ASICs), digital signalprocessors (DSPs), digital signal processing devices (DSPDs),programmable logic devices (PLDs), field programmable gate arrays(FPGAs), processors, controllers, micro-controllers, microprocessors,other electronic units designed to perform the functions describedherein, or a selective combination thereof. Such embodiments may also beimplemented by the controller 180.

For a software implementation, the embodiments described herein may beimplemented with separate software modules, such as procedures andfunctions, each of which perform one or more of the functions andoperations described herein. The software codes can be implemented witha software application written in any suitable programming language andmay be stored in memory such as the memory 160, and executed by acontroller or processor, such as the controller 180.

FIG. 2 is a front perspective diagram of a mobile terminal according toone embodiment of the present invention. The mobile terminal 100 shownin the figure has a bar type terminal body. However, the mobile terminal100 may be implemented in a variety of different configurations.Examples of such configurations include a folder-type, slide-type,rotational-type, swing-type and combinations thereof. For clarity,further disclosure will primarily relate to a bar-type mobile terminal100. However, such teachings apply equally to other types of mobileterminals.

Referring to FIG. 2, the mobile terminal 100 includes a case (casing,housing, cover, etc.) configuring an exterior thereof. In oneembodiment, the case may be divided into a front case 101 and a rearcase 102. Various electric/electronic parts are loaded in a spaceprovided between the front and rear cases 101 and 102. Optionally, atleast one middle case can be further provided between the front and rearcases 101 and 102.

The cases 101 and 102 are formed by injection molding of syntheticresin, or may be formed of a metal substance such as stainless steel(STS), titanium (Ti) or the like, for example.

A display 151, an audio output unit 152, a camera 121, user input units131 and 132, a microphone 122, an interface 180 and the like can beprovided on the terminal body, and more particularly, to the front case101.

The display 151 occupies most of a main surface of the front case 101.The audio output unit 152 and the camera 121 are provided on an areaadjacent to an end portion of the display 151, while the user input unit131 and the microphone 122 are provided on an area adjacent to anotherend portion of the display 151. The user input unit 132 and theinterface 170 can be provided to lateral sides of the front and rearcases 101 and 102.

The input unit 130 of FIG. 1 may include the input units 131 and 132 ofFIG. 2, which are manipulated to receive a command for controlling anoperation of the terminal 100. The input units 131 and 132 may bereferred to as a manipulating portion and may adopt any mechanism of atactile manner that enables a user to perform a manipulating actionwhile experiencing a tactile feeling.

Content input via the first or second input units 131 or 132 can bediversely set. For example, commands such as a start command, endcommand, scroll command and the like may be input via the first inputunit 131. Meanwhile, commands such as a command for adjusting a volumeof sound output from the audio output unit 152, a command for switchingto a touch-recognition mode of the display 151, or the like, can beinput via the second input unit 132.

FIG. 3 is a front view of a terminal according to one embodiment of thepresent invention. Various types of visual information may be displayedon the display 151. The various types of information can be displayed ascharacters, numerals, symbols, graphics, icons and the like.

In order to input the information, at least one of the characters,numerals, symbols, graphics or icons are represented as a singlepredetermined array implemented in a keypad formation on the display151. The keypad formation may be referred to as “soft keys.”

FIG. 3 shows that a touch applied to a soft key is input through a frontface of a terminal body. The display 151 is operable through an entirearea of the display or a plurality of divided regions of the display. Inthe latter case, the plurality of divided regions may be interoperablewith each other.

For example, an output window 310 and an input window 320 are displayedon the display 151. A soft key 321 representing a digit for inputting aphone number or the like is displayed in the input window 320. If thesoft key 321 is touched, a digit corresponding to the touched soft keyis displayed in the output window 310. If the first input unit 131 ismanipulated, a call connection for the phone number displayed in theoutput window 310 is attempted.

Additionally, the display 151 may be configured to receive a touch inputby scroll. A user scrolls the display 151 to shift a cursor or pointerlocated at an entity (e.g., icon or the like) displayed on the display151. When a finger is shifted on the display 151, a path of the shiftedfinger may be visually displayed on the display 151. This may be usefulin editing an image displayed on the display 151.

For clarity and convenience, the mobile terminal described in thefollowing description includes at least one of the components shown inFIG. 1. Moreover, a graphic for pointing at a specific object on adisplay unit or selecting a menu from the display unit, such as anarrow, a finger and the like, is referred to as a pointer or cursor.Yet, the term “pointer” is frequently used to indicate a finger, styluspen or the like, for performing a touch manipulation and the like. Inorder to clearly discriminate the pointer and the cursor from each otherin the disclosure, a graphic displayed on a display unit is referred toas a cursor. Meanwhile, a physical means for performing a touch,proximity touch, gesture and the like, such as a finger, stylus pen andthe like is referred to as a pointer.

In the following description, types of three-dimensional (3D)stereoscopic images and implementing methods thereof will be described.Specifically, a method of displaying a 3D image in a mobile terminalapplicable to embodiments of the present invention and a display unitconfiguration for the same will be explained.

Stereoscopic images implemented on the display unit 151 of the mobileterminal 100 according to the present invention may be classified intotwo categories. Here, the reference for this classification isattributed to whether different images are provided to both eyes of auser, respectively.

First and second stereoscopic image categories are described as follows.The first category is a monoscopic scheme of providing the same image toboth eyes and is advantageous in that it can be implemented with ageneral display unit 151. In particular, the controller 180 arranges apolyhedron generated from combining at least one of dots, lines,surfaces or a combination thereof in a virtual 3D space and enables animage, which is generated from seeing the polyhedron in a specific view,to be displayed on the display unit 151. Therefore, such a stereoscopicimage can substantially include a planar image.

The second category is a stereoscopic scheme of providing a differentimage to both eyes, respectively, which uses the principle that a usercan sense a stereoscopic effect when looking at an object with his/herown eyes. In particular, the user's eyes are configured to see differentplanar images when looking at the same object due to a distance betweenthe eyes. These different images are forwarded to the user's brain viaretinas. The user's brain is able to sense depth and reality of a 3Dimage by combining the different images together. Therefore, binoculardisparity attributed to the distance between the eyes enables the userto sense the stereoscopic effect despite the existence of an individualdifference of the binocular disparity more or less. Therefore, thebinocular disparity is an important factor of the second category. Thebinocular disparity is explained in detail with reference to FIG. 4 asfollows.

FIG. 4 is a diagram for explaining the principle of binocular disparity.Referring to FIG. 4, a hexahedron 410 is positioned as an object infront of a user's eyes below the user's eye level. Here, the user's lefteye is able to see a left eye planar image 420 revealing three facetsincluding a top side, a front side and a left lateral side of thehexahedron 410 only. The user's right eye is able to see a right eyeplanar image 430 revealing three facets including the top side, thefront side and a right lateral side of the hexahedron 410 only.Accordingly, even if an actual object is not positioned in front of theuser's eyes, so long as the left eye planar image 420 and the right eyeplanar image 430 arrive at the user's left eye and right eye,respectively, the user can substantially sense the hexahedron 410 as iflooking at an actual object.

In order to implement the 3D image belonging to the second category inthe mobile terminal 100, images of the same object should arrive at bothof the user's eyes such that the images are discriminated from eachother for the left and right eye with a predetermined parallax. In thefollowing description, 3D depth attributed to binocular disparity isexplained with reference to FIG. 5.

FIG. 5 is a diagram illustrating a sense of distance and 3D depthattributed to binocular disparity. Referring to FIG. 5, a lateral sideratio of an image entering each eye viewing a hexahedron 500 at adistance d1 from both eyes is relatively higher than that at a distanced2, whereby a difference between images seen through both eyesincreases. Moreover, an extent of a stereoscopic effect sensed by a userviewing the hexahedron 500 at the distance d1 may become higher thanthat viewing the hexahedron 500 at the distance d2. In particular, whenan object is seen through both eyes of the user, a closer objectprovides a greater stereoscopic effect, whereas a farther objectprovides a smaller stereoscopic effect.

A difference in stereoscopic effect can be digitized into a 3D depth ora 3D level. In the following description, a high stereoscopic effect ofan object situated closer shall be represented as a low 3D depth and alow 3D level. And, a low stereoscopic effect of an object situatedfarther shall be represented as a high 3D depth and a high 3D level. Asthe definition of the 3D depth or level is relatively set, aclassification reference for the 3D depth or level and anincreasing/decreasing direction of the 3D depth or level is changeable.

For clarity, in order to discriminate the above-mentioned two categoriesfrom each other, a stereoscopic image belonging to the first categorywill be referred to as a “2D stereoscopic image” and a stereoscopicimage belonging to the second category will be referred to as a “3Dstereoscopic image.”

A method of implementing a 3D stereoscopic image is described asfollows. As mentioned in the following description, in order toimplement a 3D stereoscopic image, an image for a right eye and an imagefor a left eye are to arrive at both eyes in a manner of beingdiscriminated from each other. For this, various methods are explainedas follows.

In one embodiment, a parallax barrier scheme enables different images toarrive at the user's eyes by controlling a propagating direction oflight by electronically driving a cutoff device provided between ageneral display and the user's eyes. This is explained with reference toFIG. 6 as follows.

FIG. 6 illustrates a scheme of implementing a 3D stereoscopic image in aparallax barrier type display unit according to embodiments of thepresent invention. Referring to FIG. 6, a structure of a parallaxbarrier type display unit 151 for displaying a 3D image comprises ageneral display device 151 a combined with a switch LC (liquid crystals)151 b. A propagating direction of light is controlled by activating anoptical parallax barrier 600, as shown in FIG. 6( a), using the switchLC 151 b, whereby the light is separated into two different lights toarrive at the user's left and right eyes, respectively. Thus, when animage generated from combining an image for the right eye and an imagefor the left eye together is displayed on the display device 151 a, theuser's right sees a corresponding right eye image, and the user's lefteye sees a corresponding left eye image, and thereby the userexperiences the 3D or stereoscopic effect.

Alternatively, referring to FIG. 6( b), the parallax barrier 600 of theswitch LC 151 b is electrically controlled to enable all light to betransmitted therethrough, whereby light separation due to the parallaxbarrier is avoided. Therefore, the same image can be seen by the user'sleft and right eyes. In this case, the same function of a conventionaldisplay unit is performed.

FIG. 6 exemplarily shows that the parallax barrier performs paralleltranslation in one axial direction, by which the present invention isnon-limited. Alternatively, the present invention a parallax barrier maybe used that enables parallel translation in at least two axialdirections according to a control signal from the controller 180.

In another embodiment of the invention, a lenticular scheme relates to amethod of using a lenticular screen provided between a display and theuser's eyes. In particular, a propagating direction of light isrefracted via lens on the lenticular screen, whereby different imagesarrive at each of the user's eyes, respectively.

In another embodiment of the invention, according to a polarized glassesscheme, polarizing directions are set orthogonal to each other toprovide different images to each of the user's eyes, respectively. Incase of circular polarization, polarization is performed having adifferent rotational direction, whereby different images can be providedto each of the user's eyes, respectively.

In another embodiment of the invention, an active shutter scheme issimilar to the polarized glasses scheme. Here, a right eye image and aleft eye image are alternately displayed on a display unit with aprescribed periodicity. And, a pair of glasses worn by the user closesan opposing shutter when an image of a corresponding direction isdisplayed. Therefore, the image of the corresponding direction arrivesat the user's eye in a corresponding direction. Specifically, while theleft eye image is displayed on the display unit, a shutter for the righteye is closed to enable the left eye image to arrive at the left eyeonly. On the contrary, while the right eye image is displayed on thedisplay unit, a shutter for the left eye is closed to enable the righteye image to arrive at the right eye only.

In the following description, a mobile terminal according to oneembodiment of the present invention is able to provide a user with a 3Dstereoscopic image via the display unit 151 by one of the abovedescribed methods. Because the 3D image principle described withreference to FIG. 5 and FIG. 6 provides for a stereoscopic object, theobject of a left eye image differs from the object of a right eye imagein shape. Yet, if an object is not a stereoscopic object but a planarobject, a shape of the object of a left eye image is identical to ashape of the object of a right eye image. If a position of the object ofthe left eye image is different from that of the object of the right eyeimage, a user is able to view the corresponding object in theperspective. To help understand the present invention, a stereoscopicimage in the following description is a planar object. However, it isapparent to those skilled in the art that the description below isapplicable to a stereoscopic object as well.

FIG. 7 is a diagram for describing stereoscopy of a planar objectaccording to an embodiment of the present invention. Referring to FIG.7, a distance between the user's eyes 770 and a first planar object 710is set to d. Moreover, three planar objects 720, 730 and 740 existbetween the user's eyes 770 and the first planar object 710 at distancesless than d from the user's eyes, respectively.

In order to provide the user with a stereoscopic or cubic effectaccording to an arranged formation of the planar objects shown in FIG.7( a), a different 3D depth is provided to each of the planar objectsaccording to a distance from the user's eyes. As a result, aconfiguration resulting from overlapping left and right eye images witheach other can be represented as shown in FIG. 7( b). Here, the drawingsrepresenting the eye image overlapped configurations including theconfiguration shown in FIG. 7( b) are provided to help understand thedifference between the images of the objects for the user's eyes. And,images actually displayed on the display unit may be different from theconfigurations shown in the drawings according to 3D stereoscopic imageimplementing schemes.

Referring to FIG. 7( b), a position of each of the objects 730 and 740within the left eye and right eye images appearing closer to the user isdifferent from a position of the object 720 appearing relatively fartherfrom the user. The object 710, which appears no different between theleft eye and right eye images, is seen at a position corresponding to adistance between the eyes 770 and the display unit 151.

For clarity, in the following description, a point having no positiondifference between a left eye image and a right eye image is referred toas a convergence point, and an object having no position differencebetween a left eye image and a right eye image is referred to as aconvergence object. Therefore, the larger the difference of the object'sposition between the the left eye image and the right eye image, thelarger a 3D depth difference from a convergence point sensed by theuser.

Moreover, if an object has a larger 3D depth difference from aconvergence point, a difference between the object's position within theleft eye image and right eye image increases. This is explained withreference to FIG. 8 as follows.

FIG. 8 is a diagram of a display configuration resulting from combiningright eye and left eye images together to indicate a difference betweenan object's position in the images according to an embodiment of thepresent invention. Referring to FIG. 8, a distance difference 810between a position of a flowerpot object within a left eye image and theposition of the flowerpot object within a right eye image, or a distancedifference 820 between a position of a dish object in the left eye imageand the position of the dish object within the right eye image, isrelatively larger than that of other objects. Here, although astereoscopic effect experienced by a user is raised, if the distancedifference between the positions of a corresponding object within therespective left eye and right eye images exceeds a predetermined range,the user may experience dizziness, or other visual inconvenience.According to an embodiment, the predetermined range may be a distance of5 cm to 7 cm, for example, corresponding to a distance between the leftand right eyes of an ordinary user.

According to one embodiment of the present invention, a position of anobject within a left eye image or right eye image may be determined andcorrected. For example, when the object's position exceeds a criticaldistance, a user experiences visual inconvenience due to a differencebetween positions of the object within the right eye and left eyeimages, respectively. Therefore, the present invention provides for amobile terminal and controlling method thereof for enabling therespective positions of the object within the right eye and left eyeimages to be shifted within the critical distance automatically oraccording to the user's command input.

The present method can be performed via the following steps. First, thecontroller 180 searches for a same object within a left eye image and aright eye image. The same object may be searched by performing a blocksearch algorithm, an object tracking algorithm or the like. Principlesof the algorithms will be described in detail below.

Next, the controller 180 determines a distance difference between aposition of the same object within the left image and a position of thesame object within the right eye image. Finally, if the distancedifference between the positions of the same object within the left eyeand right eye images exceeds a predetermined critical value, thecontroller 180 corrects a position of the corresponding object in eachof the left eye and right eye images to cause the distance difference tobecome equal to or less than the critical value. The controller 180 maythen display each of the corrected images via the display unit.

The above described algorithm is merely exemplary, by which the presentinvention is non-limited. Alternatively, various types of algorithms maybe used by the controller 180 to determine and correct a position of thesame object within a left eye and right eye image.

In accordance with an embodiment of the present invention, a blocksearch algorithm is described. The block search algorithm is a type ofalgorithm used by the controller 180 to search for the same objectwithin a left eye image and a right eye image. According to the blocksearch algorithm, each of the left eye image and the right eye image issearched for a block having a highest correlation there between. Adisplacement of the corresponding block is then determined. A process ofsearching for blocks having the highest correlation between the left eyeand right eye images may be referred to as image estimation. A vectorfor estimating a motion of the corresponding block in each of the lefteye and right eye images may be referred to as an estimation vector.This is described with reference to FIG. 9 as follows.

FIG. 9 illustrates a block search algorithm applicable to one embodimentof the present invention. FIG. 9( a) illustrates a left eye image for aleft eye. Referring to FIG. 9( a), a left eye image can be divided intoblock units having a certain size. According to the block searchalgorithm, a macro block 920 including at least one portion of aspecific object 910 may be a target of image estimation within a righteye image for a right eye, as shown in FIG. 9( b). As a result of ashift by a displacement corresponding to an estimation vector in theright eye image, the controller 180 may detect a block 930 of the righteye image most correlated to the macro block 920 of the left eye image.

The controller 180 may use the estimation vector to obtain coordinatesof a corresponding object in each of the left eye and right eye images.Moreover, as mentioned in the foregoing description, in order to searchthe left eye image and the right eye image for the same object, thecontroller 180 may use an object tracking algorithm as well as the blocksearch algorithm. According to the object tracking algorithm, an objectis recognized in one of the left eye image or right eye image byfeature-point extraction and the like. The recognized object is thentracked in the other of the left eye image or right eye image.

The controller 180 obtains the coordinates of the object in each of theleft eye and right eye images using one of the above-mentionedalgorithms. The controller 180 is also able to calculate a distancedifference between the position of the object within the left eye imageand the position of the object within the right eye image. This isexplained with reference to FIG. 10 as follows.

FIG. 10 illustrates a method of calculating a distance differencebetween a position of an object appearing in a left eye image and aposition of an object appearing in a right eye image according to oneembodiment of the present invention. FIG. 10( a) shows a left eye image,FIG. 10( b) shows a right eye image, and FIG. 10( c) shows an imageresulting from combining the left eye and right eye images together.

Referring to FIG. 10, if coordinates of an object 1010 positioned in aleft eye image correspond to (x, y) and coordinates of an object 1020positioned in a right eye image correspond to (x′, y′), a distancedifference 1030 between the object appearing in the left eye image andthe object appearing in the right eye image is equal to a square root of(x′−x)²+(y−y′)². If y is equal to y′, the distance difference 1030 isequal to (x′−x).

Accordingly, in order to make the distance difference between thepositions of the object in the respective left eye and right imagesbecome equal to or less than a critical value, a position of the objectin each of the left eye and right images is corrected. Preferably, thepositions of the object are moved by the same distance closer to acenter in each of the left eye and right eye images, wherein the centeris a central location between the position of the object in the left eyeimage and the position of the object in the right eye image.

For example, referring to FIG. 10( c), the center in each of the lefteye and right images is equal to [(x−x′)/2, (y−y′)/2]. If the distancedifference 1030 is 10, and a preset critical value is 7, it ispreferable that the position of each of the objects in the respectiveleft eye and right eye images is shifted toward the center by 1.5. Inparticular, if y is equal to y′, the object 1010 positioned at thecoordinates (x, y) is shifted toward the center, i.e., to the right inthe left eye image. Hence, the position of the object 1010 in thecorrected left eye image is [(x+1.5), y].

A method for applying the above described algorithms to a stereoscopicobject shown in FIG. 8 is described with reference to FIG. 11 asfollows. FIG. 11 illustrates display configurations for searching leftand right eye images for the same object in a mobile terminal accordingto one embodiment of the present invention.

FIG. 11( a) shows blocks used in connection with the block searchalgorithm to detect a same object in an image resulting from overlappinga left eye image and a right eye image together. Referring to FIG. 11(b), a flowerpot object 1130 and a dish object 1140 are detected in theleft eye image 1110 and the right eye image 1120 and displayed via theobject tracking algorithm.

Once the positions of the objects are detected in the left eye and righteye images by one of the above described methods, respectively, positioncorrection can be performed. As shown in FIG. 12, position correction isperformed on the object whose distance difference between a position inthe left eye image and a position in the right eye image exceeds apreset critical distance.

FIG. 12 illustrates a scheme for performing position correctionaccording to one embodiment of the present invention. Referring to FIG.12( a), the controller 180 determines whether a distance difference 1210of the flowerpot object in each of the left eye and right eye imagesexceeds a preset critical value in the image resulting from combiningthe left eye image and the right eye image. The controller 180 alsodetermines whether a distance difference 1220 of the dish object in eachof the left eye and right eye images exceeds a preset critical value inthe image resulting from combining the left eye image and the right eyeimage. Referring to FIG. 12( b), the controller 180 is able to correcteach of the images to decrease a distance difference 1230 of theflowerpot object and a distance difference 1240 of the dish object.Therefore, the problem related to a user's visual discomfort and/orinconvenience due to an excessive distance difference is resolved.

The above-explained position correction example shown in FIG. 12 isfurther described with reference to FIG. 13 as follows. FIG. 13illustrates a scheme for performing position correction according to oneembodiment of the present invention.

Referring to FIG. 13( a), a triangle in each of a left eye image and aright eye image becomes a convergence object. Due to a positiondifference between a face shape appearing at a left portion of the lefteye image and a face shape appearing at a right portion of the right eyeimage, a user is able to sense a stereoscopic effect with respect to theface shapes. However, when a distance 1310 between the face shapes inthe left eye and right eye images exceeds a predetermined criticalvalue, visual discomfort is experienced by the user. To relieve theuser's discomfort, the respective face shapes in the left eye and righteye images can be shifted closer to the center in each of the images. Bydoing so, a distance 1320 between the face shapes is shortened to beless than the predetermined critical value, as shown in FIG. 13( b),thereby relieving the user of the visual discomfort.

In an embodiment of the present invention, image compensation accordingto position correction of an object is considered. Specifically, when aspaced distance exceeding a critical distance of the same object in eachof a left eye image and a right eye image is adjusted according to oneembodiment of the present invention, loss of, or loss to, an originalimage may occur due to a shift of the object. To solve this problem, animage loss compensating method according to an embodiment of the presentwill be described with reference to FIG. 14 as follows.

FIG. 14 illustrates a method of compensating an image according to anembodiment of the present invention. In FIG. 14, objects are arrangedsimilar to the objects in FIG. 13. Referring to FIG. 14( a), as anobject 1410 is shifted toward a center by a correcting method accordingto one embodiment of the present invention, a space 1420, correspondingto image information having a crescent moon shape may be lost. That is,a lost space is generated in a region not overlapped by a regionoccupied by the shifted object 1410.

Thus, if the lost space, from which the image information is lost, isdisplayed as is, image quality is degraded. Therefore, the presentembodiment performs image compensation using image information from anopposing image corresponding to the lost space.

For example, image information having a crescent moon shapecorresponding to the lost space 1420 generated in a left eye image, asshown in FIG. 14( a), may be retrieved from a right eye image andinserted into the lost space of the left eye image, as shown in FIG. 14(b). Conversely, a space lost in the right eye image may be filled withcorresponding image information from the left eye image. Moreover, incase of video, image information corresponding to a lost space may beretrieved from a frame next or previous to a corresponding frame.

In accordance with another embodiment of the present invention, a methodfor optimizing a critical distance for a user will be described.Specifically, in the following description, a method of setting acritical distance per user will be explained with reference to FIG. 15.

FIG. 15 illustrates a method of measuring and setting a criticaldistance applicable to embodiments of the present invention.

Referring to FIG. 15, a user may perform a prescribed menu input via theuser input 130 to enter a menu for measuring/setting a criticaldistance. If the menu is entered, both a left eye image 1510 and a righteye image 1520 may be displayed on the display unit 151 for measuringand/or setting a critical distance.

An object 1511 having a prescribed shape is displayed on each of theleft eye image 1510 and the right eye image 1520. The user may thenchange a distance difference between a position of the the object 1511on the left eye image and a position of the object 1511 on the right eyeimage, as shown in FIGS. 15( a) and 15(b). While changing the distancedifference between the positions of the object 1511 respectivelydisplayed on the left eye image 1510 and the right eye image 1520, theuser can measure/determine the distance difference on the display unit151 at which visual discomfort is experienced by the user. Accordingly,the user may then set a critical value for the measured distancedifference, via a prescribed menu manipulation, to avoid experiencingthe visual discomfort.

In accordance with another embodiment of the present invention, a methodfor manual and automatic distance difference correction will bedescribed. In this embodiment, the controller 180 determines/identifiesan object whose distance difference between its position in a left eyeimage and its position in a right eye image exceeds a prescribedcritical distance. The controller 180 then informs a user of thedetermined/identified object by displaying the determined/identifiedobject on the display unit. Moreover, the controller 180 enables theuser to select whether to perform distance difference correction on thedetermined/identified object. This embodiment will be explained withreference to FIG. 16 as follows.

FIG. 16 illustrates a method of correcting a stereoscopic imageaccording to another embodiment of the present invention. In FIG. 16, aleft eye image and a right eye image are overlapped with each other.

Referring to FIG. 16( a), the controller 180 determines/identifiesobjects 1610, 1620, of which a distance difference between a position ofthe respective object in the left eye image and a position of therespective object in the right eye image exceeds a prescribed criticaldistance. The determined/identified objects 1610, 1620 are displayed onthe display unit 151 with a prescribed visual effect to help the userrecognize the determined/identified objects 1610, 1620. Such a displayfunction may be turned on through a prescribed menu setting if thereexists an object causing visual discomfort to the user. Alternatively,such a display function can be executed only if the user manipulates aspecific key button (e.g., a hardware key button, a virtual key button,etc.). Optionally, each of the determined/identified objects may bedisplayed with a different visual effect according to a 3D depthdifference from a convergence point.

If the display unit 151 includes a touchscreen configured to recognize auser's touch input, the user may select one of the determined/identifiedobjects using a finger 1630 or a stylus pen. If the display unit 151does not include the touchscreen, the user may select one of thedetermined/identified objects by manipulating a cursor displayed on thedisplay unit 151. If the object is selected, the controller 180 narrowsthe selected object's distance difference to within a preset criticaldistance range. Alternatively, if the object is selected, the controller180 narrows the selected object's distance difference by a predeterminedvalue each time the selection is made.

Referring to FIG. 16( b), if the determined/identified object isselected, a menu window 1640 is displayed for enabling a user to selectautomatic distance difference correction (Auto) or manual distancedifference correction (Manual). If automatic distance differencecorrection is selected, the distance difference between the position ofthe selected object in the left eye image and the position of theselected object in the right eye image is narrowed to within the presetcritical distance. If manual distance difference correction is selected,the distance difference between the position of the selected object inthe left eye image and the position of the selected object in the righteye image is narrowed by a predetermined value each time the selectionis made. Alternatively, a scroll bar 1650 configured to adjust an extentof narrowing the distance difference may be displayed, as shown in FIG.16( c).

Moreover, in accordance with the embodiment, after an image prior to thecorrection of the left eye and right eye images is displayed on thedisplay unit, a corrected image may be displayed while a user inputunit, such as a specific hardware key button or specific virtual keybutton, is manipulated. Such a function may be referred to as acorrected image preview function.

An example of a type of setting menu configuration for setting theabove-mentioned methods of correcting a stereoscopic image is describedwith reference to FIG. 17. FIG. 17 illustrates an example of a menuscreen for setting a method of correcting a stereoscopic imageapplicable to embodiments of the present invention.

Referring to FIG. 17, menus for setting a stereoscopic image correctingmethod can include an automatic or auto correction menu, an autocorrection distance menu, a total collective correction menu, a manualcorrection step menu, a convergence point display menu and the like.

The auto correction menu is a menu for setting a function forautomatically narrowing a distance difference between a position of anobject displayed in a left eye image and a position of the objectdisplayed in a right eye image to within a critical distance range,wherein the pre-narrowed distance difference exceeds a preset criticaldistance.

The auto correction distance menu is a menu for setting theabove-mentioned preset critical distance. The audio correction distancemenu is set by the method described with reference to FIG. 15, or can beset directly by user input.

If the distance difference is automatically narrowed to within thecritically distance range, the total collective correction menu allowsfor the application of a narrowing ratio to all displayed objects exceptfor the object whose distance difference exceeds the preset criticaldistance. Accordingly, the 3D depth of the object whose distancedifference exceeds the preset critical distance and the 3D depths of allobjects except a convergence object can be adjusted in proportion to the3D depth of an object having a maximally adjustable 3D depth.

If the user selects manual distance difference correction, as shown inFIG. 16( a) or 16(b), the manual correction step menu of FIG. 17 sets anextent of narrowing the distance difference each time a selection ismade. The convergence point display menu is a menu for providing aprescribed visual effect to a convergence point in order to provide auser with a reference point of the distance difference correction.

The above-described menu configurations and names are merely exemplary,by which the present invention is non-limited. Various types of menuconfigurations and names may be applicable to the present invention.

In addition, the above-described methods can be implemented in a programrecorded medium as computer-readable codes. The computer-readable mediainclude all types of recording devices in which data readable by acomputer system is stored. The computer-readable media include ROM, RAM,CD-ROM, magnetic tapes, floppy discs, optical data storage devices, andthe like for example and also include carrier-wave type implementations(e.g., transmission via Internet).

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the present inventionwithout departing from the spirit or scope of the invention. Thus, it isintended that the present invention covers the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

1. A mobile terminal comprising: a controller; and a display unitcontrolled by the controller and configured to display a stereoscopicimage, the stereoscopic image comprising a first image provided to aleft eye of a user and a second image provided to a right eye of theuser, wherein the controller: detects at least one same object betweenthe first and second images, and determines a distance between a pointat which the detected at least one same object is positioned in thefirst image and a point at which the detected at least one same objectis positioned in the second image, wherein when the determined distanceis equal to or greater than a preset critical value, the controllerchanges a position of the at least one same object in each of the firstand second images to decrease the distance between the point at whichthe at least one same object is positioned in the first image and thepoint at which the at least one same object is positioned in the secondimage to less than the preset critical value, and wherein the controllerdisplays the changed first and second images on the display unit.
 2. Themobile terminal of claim 1, wherein the display unit comprises an imagedisplaying means and a parallax generating means provided over the imagedisplaying means to change at least one of a propagation direction and avibration direction of a light generated from the image displayingmeans.
 3. The mobile terminal of claim 1, wherein the controller detectsthe at least one same object between the first and second images by ablock search algorithm or an object tracking algorithm.
 4. The mobileterminal of claim 1, wherein the controller changes the position of theat least one same object in each of the first image and second image bymoving the at least one same object closer to a center point between thepoint at which the at least one same object is positioned in the firstimage and the point at which the at least one same object is positionedin the second image by the same distance.
 5. The mobile terminal ofclaim 1, wherein the controller displays the at least one same objectwith a prescribed visual effect before changing the position of the atleast one same object.
 6. The mobile terminal of claim 5, furthercomprising a user input unit configured to receive a user command,wherein if the at least one same object with the prescribed visualeffect is selected by the user command, the controller only changes aposition of the selected object in each of the first image and secondimage.
 7. The mobile terminal of claim 6, wherein each time theselection is made, the controller changes the position of the selectedobject by a predetermined distance.
 8. The mobile terminal of claim 5,further comprising a user input unit configured to receive a usercommand, wherein if the at least one same object with the prescribedvisual effect is selected by the user command, the controller displays amenu window in the vicinity of the selected object to enable the user toselect a manual execution of the position change or an automaticexecution of the position change of the selected object.
 9. The mobileterminal of claim 8, wherein if the manual execution is selected fromthe menu window, the controller displays a scroll bar for adjusting adistance of the position change of the selected object.
 10. The mobileterminal of claim 8, wherein if the automatic execution is selected fromthe menu window, the controller changes the position of the selectedobject in each of the first image and second image such that thedistance between the point at which the selected object is positioned inthe first image and the point at which the selected object is positionedin the second image is less than the preset critical value.
 11. Themobile terminal of claim 5, wherein the controller displays aconvergence object positioned at a same position in the first and secondimages with a different prescribed visual effect according to a relativelevel of a stereoscopic effect of the at least same object.
 12. Themobile terminal of claim 1, wherein the first image and the second imagecorrespond to one video frame, wherein when the position of the at leastone same object is changed in each of the first image and second image,if a lost space is generated in the one video frame, the controllercontrols an image corresponding to the lost space to be inserted in avideo frame next to or previous to the one video frame.
 13. The mobileterminal of claim 1, wherein when the position of the at least one sameobject is changed in one of the first image and second image, if a lostspace is generated, the controller controls an image corresponding tothe lost space in the other of the first image and second image to beinserted in the lost space in the one of the first image and secondimage.
 14. The mobile terminal of claim 1, wherein the preset criticalvalue is a distance corresponding to a binocular interval of the user.15. A method of controlling a mobile terminal, the method comprising:detecting at least one same object between a first image and a secondimage displayed on a display unit, wherein the first image and secondimage together form a stereoscopic image; calculating a distance betweena point at which the detected at least one same object is positioned inthe first image and a point at which the detected at least one sameobject is positioned in the second image; determining whether thecalculated distance is equal to greater than a preset critical value,when the calculated distance is equal to or greater than the presetcritical value, changing a position of the at least one same object ineach of the first and second images to decrease the distance between thepoint at which the detected at least one same object is positioned inthe first image and the point at which the detected at least one sameobject is positioned in the second image to less than the presetcritical value; and displaying the changed first and second images onthe display unit.
 16. The method of claim 15, further comprisingdetecting the at least one same object between the first and secondimages by a block search algorithm or an object tracking algorithm. 17.The method of claim 15, wherein changing the position of the at leastone same object in each of the first image and second image comprisesmoving the at least one same object closer to a center point between thepoint at which the at least one same object is positioned in the firstimage and the point at which the at least one same object is positionedin the second image by the same distance.
 18. The method of claim 15,further comprising displaying the at least one same object with aprescribed visual effect before changing the position of the at leastone same object.
 19. The method of claim 15, wherein the first image andthe second image correspond to one video frame, wherein when theposition of the at least one same object is changed in each of the firstimage and second image, if a lost space is generated in the one videoframe, controlling an image corresponding to the lost space to beinserted in a video frame next to or previous to the one video frame.20. The method of claim 15, wherein when the position of the at leastone same object is changed in one of the first image and second image,if a lost space is generated, controlling an image corresponding to thelost space in the other of the first image and second image to beinserted in the lost space in the one of the first image and secondimage.
 21. The method of claim 15, wherein the preset critical value isa distance corresponding to a binocular interval of a user.